The Hepatitis B Research Network (HBRN) was established to promote research in hepatitis B focusing upon elucidating the pathogenesis and natural history and developing means of treatment and control. The HBRN is a Cooperative Agreement that includes 28 collaborating Clinical Centers at 13 consortia, an Immunology Center, a NIDDK Project Scientist and a NIDDK Project Official, and a Data Coordination Center (DCC). The HBRN includes 2 natural history studies, one that includes adults and the other pediatric participants with hepatitis B virus (HBV) infection. There are also 3 clinical trials and2 studies of immunological parameters. As the DCC, we work with the HBRN members to support all aspects of study design, study conduct, and data analysis for the various studies. In collaboration with HBRN personnel, we developed data collection instruments and processes to facilitate collecting complete and accurate data. We developed and maintain the distributed data entry system and maintain a secure, central database of clinical, laboratory, and other relevant information from the Clinical and Immunology Centers. We have identified, and contract with, other central facilities (virology laboratory, DNA extraction, pathology staining, drug distributio) and coordinate with the NIDDK-funded Biosample and Data Repositories. We collaborated with developing safety and efficacy analysis plans and prepare materials for presentations at HBRN meetings, scientific conferences, and for publications and oversight and regulatory bodies. The DCC coordinates all activities of the HBRN, including meetings and conference calls for the Steering Committee, subcommittees, and presentations to the Data and Safety Monitoring Board(s). We serve on all subcommittees, monitor and facilitate the Publications and Presentations and Ancillary Studies subcommittee processes. We will share data collected for the HBRN, participate in translation activities with the wider scientific, clinical, and general community and archive all data, study intervention materials, and coordinate archiving all specimens at the end of the study.